Will 318, 340 or 360 heads fit on a 273?

I have 318 heads on my 1965 Barracuda 273. I believe the valves are a little larger on the 318 heads. Check it out.
If you ever want to use the Performer aluminum intake manifold on a 273, the 318 heads match the angles of the intake manifold whereas the 1965, and I think the 1966, 273 head angles do not exactly match this manifold. You can bolt them up, but you will have vacuum leaks. Edelbrock says this manifold fits the 1965 273. Uh-Uh.